In the field of machine washing of laundry, the Applicant Company is already the owner or titleholder of a number of patent applications, which may be mentioned by way of reference to illustrate the state of the art.
The application FR No. 84/06,151, filed on Apr. 18, 1984 for "Process for washing linen in a machine with a liquid detergent and device for its application" relates particularly to a device, generally reloadable, which is firstly filled with liquid detergent and is then placed in the drum of the machine with the laundry to be washed. The detergent contained in the device diffuses gradually into the washing medium and into the laundry placed in the machine. In one embodiment, the device comprises a filling orifice and vents for the gradual release of the the liquid within the laundry during the washing operation.
Patent Application FR No. 84/13,210, filed on Aug. 24, 1984 for "Device for washing in a machine with a detergent liquid and process employing the said device" relates to a device of the above type, which is more particularly characterized in that it is of a substantially spherical shape. A certain number of orifices permit the liquid to diffuse.
It is known, furthermore, that the use of liquid washing aids gives rise to individual difficulties because of the risks of incompatibility of some of their constituents.
Thus, although it is possible to package the constituents of a powdered washing aid in the same container, it is not permissible in practice to formulate liquid washing aids in advance when their formulations contain, at the same time as the other active constituents, constituents capable of releasing active oxygen or chlorine, for example peroxidic constituents of the type of perborates or other inorganic or organic peroxidic salts. It is known, however, that the presence of active oxygen or chlorine is quite desirable if optimum effectiveness is to be obtained. In the case of liquid washing aids, attempts are being made, therefore, to produce formulations containing the same basic combinations as those in the granular or powdered detergents. However, practical impossibilities then stand in the way, because it is known that when traditional active components and perchlorinated or peroxidic components are incorporated together within a liquid washing aid, these compounds rapidly lose their effectiveness. Thus, it has been found that after storage periods of the order of two weeks, the active oxygen of these peroxidic compounds is practically completely released, thus becoming available at the time of use in the wash bath.
By the way of reference which illustrates the state of the art, there may be mentioned the European Patent Application published under No. 0,132,726, which describes the use of a package in the form of a sachet containing a substance as well as another sachet of smaller size containing another substance which is not compatible with the first. The material of which the outer sachet is made is water-permeable, as is that of the inner sachet, but the materials are chosen so as to permit the diffusion of the substances which they contain at different temperatures, which enables the packaging to be adapted to practical needs, for example of washing. The teaching of this prior document consists therefore in presenting in the same packaging individual sachets capable of containing liquid substances, choosing the sachets so that they release the substances which they contain at different temperatures. Such packaging containers are single-use and comprise a plurality of compartments, the basic concept resulting in an application of the substances held in each of the individual sachets which is necessarily offset in time. Furthermore, it is essential that the latter be soluble in water or have particular properties in order to allow water to pass at a specific temperature. This is why the outer sachet is made from a sheet of open-pore polyurethane foam, while the inner sachet consists of polyvinyl alcohol.